Known in the art are devices for checking on the correct functioning of DST transformers.
Such devices have the disadvantage that they do not perform the measurement of the Very High Voltage (VHV) and do not perform the function as a real stage of horizontal deflection.
Moreover, failure indication is implemented by a light-emitting diode (LED), which does not allow a differentiation between the possible errors which lead to poor functioning of the DST transformer.
This means that it is not possible to determine the type of failure, and this does not ensure speedy diagnosis of the possible failure.
Furthermore, said devices do not detect lower VHV levels for cathode ray tubes, which lead to poor functioning of said tubes, since the power needed for the correct operation of the cathode ray tubes is higher than the power supplied by the DST transformer.